title: Normal esophageal body function: a study using ambulatory esophageal manometry.
abstract: OBJECTIVE
  The objective of this study was to establish normative ambulatory manometric data for contractions and contraction propagation in three levels of the esophagus.
  
  
  METHODS
  Twenty-five healthy volunteers underwent simultaneous ambulatory 24 h manometry. Concomitant 24 h pH studies were performed to exclude the presence of increased esophageal acid exposure. Pressures were recorded over a complete circadian cycle while patients continued with their normal lifestyles including eating and sleeping. Data were analyzed with a software program that was previously modified and validated and that enables quantitation of contractions in terms of efficacy.
  
  
  RESULTS
  The frequency of contractions was lowest during sleep, was increased when awake, and was highest during meals. Contraction amplitude increased during meals, providing a greater propulsive force for bolus transport. Similarly, the prevalence of peristaltic waves varied according to different physiologic states, ie., while eating, upright, awake, and sleeping. An increased amplitude and prevalence of peristalsis resulted in an increase in manometric efficacy during meals.
  
  
  CONCLUSIONS
  This study provides normative data for ambulatory manometry for comparison when studying patients with disease.
authors.affiliation: University of Southern California School of Medicine, Department of Surgery, Los Angeles 90033-4612, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Bremner
authors.forename: M
authors.initials: M
authors.lastname: Costantini
authors.forename: T R
authors.initials: TR
authors.lastname: DeMeester
authors.forename: C G
authors.initials: CG
authors.lastname: Bremner
authors.forename: S F
authors.initials: SF
authors.lastname: Hoeft
authors.forename: P F
authors.initials: PF
authors.lastname: Crookes
authors.forename: J H
authors.initials: JH
authors.lastname: Peters
authors.forename: J A
authors.initials: JA
authors.lastname: Hagen
mesh_terms: D000328:Adult; D004947:Esophagus / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008365:Manometry; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D010528:Peristalsis; D011312:Pressure; D012016:Reference Values